The objective of this proposal is to determine the viability of creating antibodies to catalyze desired polymerizations. It is expected that a specially elicited antibody will stereospecifically catalyze an esterification reaction, a catalysis already demonstrated by antibodies. Furthermore, it would be an important advance in the repertoire of catalytic antibodies if the esterification could be repeated multiple times to create a desired polymer. This is proposed for the formation of novel polylactide polymers, which are currently the most important constituents of polymer drug delivery systems. The specific aims of the proposal are to determine if it is possible to polymerize difunctional compounds by specially elicited antibodies and use this technique to make a novel syndiotactic polylactide for useful drug delivery systems. The specific aims also include characterization of the rate, mechanism, specificity and degree of polymerization of any antibodies that are catalytically active.